The WhatsApp Business 24-hour window: how it works
On the WhatsApp Business API, free-form replies to a customer are only allowed for 24 hours after their last message — a WhatsApp rule, not an AISAR one. Here's how AISAR tracks that window, what an operator sees in chat, and what to do once it has closed.
What you need to know
- The window applies only to the WhatsApp Business API (WABA) — regular personal WhatsApp has no such limit, you can write at any time.
- The clock runs from the customer's last inbound message: once they write, you have 24 hours to reply freely with plain text, files and buttons — no Meta moderation involved.
- 24 hours after their last message with no new one from the customer, the window closes — plain text no longer works, and you need a message template Meta has already approved.
- Any new inbound message from the customer reopens the window for another 24 hours, even if it arrives right after the previous one closed.
What this looks like in chat
While the window is open, nothing special shows in the interface — the conversation behaves normally. As soon as it closes, the message composer for that customer's conversation shows a warning: "The 24-hour window is closed — only an approved template can be sent to this customer." Sending plain text at that point fails — pick a message template from the Templates section instead.
A direct API attempt to send plain text outside the window gets rejected by WhatsApp with error code 131047, described as "more than 24 hours since the customer last replied — only an approved template can be sent outside the session."
What still works outside the window
- Send an approved template. The only way to message the customer first outside the window is a message template Meta has already approved. For how to create and get one approved, see WABA templates: categories, creation, variables.
- Wait for a new message from the customer. As soon as they write again — for any reason — the window reopens for 24 hours, and free-form replies work again.
Common issues
| Symptom | Cause and what to do |
|---|---|
| A message won't send, and a window warning shows | The window has closed. Send an approved template instead of plain text, or wait for a new message from the customer. |
| A direct API request returns error 131047 | Same situation — more than 24 hours have passed since the customer's last inbound message. Switch to sending a template. |
| The window seems to have closed earlier than expected | The clock runs from the customer's last inbound message, not from your last reply or the start of the conversation — check when they actually wrote last. |
| A sent template still fails to deliver | Check the template is "Approved" with Meta, the language matches, and the variables are filled in — see Why a WABA template got rejected and what to do. |
See also
For creating and getting templates approved, see WABA templates: categories, creation, variables. If Meta rejected a template, see Why a WABA template got rejected and what to do. For connecting the channel itself, see Connecting WhatsApp Business (WABA).